Scientists say frequent ejaculations could be the key to keeping the semen-producing gland healthy and avoiding cancer.

In fact, in a study of almost 32,000 men published in the journal of European Urology, researchers found high levels of sexual activity can reduce the risk of contracting prostate cancer by 33 per cent.

The optimum number is 21 ejaculations per month.

We've done a few quick calculations and that's equal to 252 times annually — or almost 70 per cent of days in a year.

Experts aren't exactly sure why ejaculation lowers the risk of prostate cancer, but they speculate it might help flush out cancer-causing toxins.